This upgrade is the D&D Stage One upgrade using two of the intake side camshafts from the naturally aspirated 1100 Arctic Cat motor. These cams are a stage one upgrade for the Z1 Turbo and 1100 Turbo ProCross/ProClimb; for use with big turbo kits including the 2860 and larger turbos. We like to see these run at 8800 RPM.